Sea Level Changes

Question 1

Sea level changes are…

Answer 1

Eustatic or isostatic

Question 2

Eustatic sea level change

Answer 2

A global change in sea level resulting from a fall or rise in the level of the sea itself (volume of water in the sea changes/change in the shape of the ocean basins)

Question 3

Eustatic change causes (2 points)

Answer 3

1. Changes in climate
   - increase in temp = ice sheets melt, water expands (increased sea level)
   - decrease in temp = more snow, more water stored in glaciers so volume of sea is reduced (sea level decreases)
2. Tectonic movement
   - shape of ocean basins are altered and thus volume also

Question 4

Eustatic change always has g______ effects

Answer 4

GLOBAL

Question 5

Downward movement of the land causes…

Answer 5

Sea level to rise locally

Question 6

Uplift of land causes…

Answer 6

Sea level to fall

Question 7

Isostatic sea level change

Answer 7

Local changes in sea level resulting from the land rising and falling relative to the sea

Question 8

Even today, ___ years after the last ___ _____ ended the UK is still readjusting to not having its ___ load

Answer 8

10 million
Ice age
Icy

Question 9

UK Isostatic Change Situation

Answer 9

The north of the UK is rising, e.g Ben Nevis at 2mm per year

The south of the UK is sinking, e.g Brighton at -0.4mm per year

Question 10

The main causes of isostatic sea level change are… (3 points)

Answer 10

1. Uplift/depression of Earth’s crust
   - Melting ice sheets = uplift as no more weight on land (rebound)
   - Accumulation of sediment = depression
2. Subsidence of land
   - caused by shrinkage of land after abstraction of groundwater
3. Tectonic processes

Question 11

Tectonic movement leads to an _______ in surface area of land. This means that the water is more ____________ into a ___________ area and so ocean depths increase.

Answer 11

Increase
Condensed
Smaller

Question 12

Tectonic Process Explanation

Answer 12

1. Global temps cool, ice forms as glaciers and ice sheets
2. These ice forms reduce water in oceans (eustatic fall)
3. The relative fall in sea level is moderated by the ice that forces land to move down (Isostatic change)
4. Climate warms ice melts sea level rise
5. Flooding occurs, submergent features form
6. Once ice is removed Isostatic rebound can occur - slow
7. Prolonged rebound - allows emergent features such as raised beaches which sit above sea level

Question 13

Isostatic changes + eustatic changes =

Answer 13

FLOODING

Land sinking and sea level rising

Question 14

Sea level has _____ in the last _________ years

Answer 14

Risen

10,000

Question 15

Sea level varies on a _____ basis with the tidal cycle.

Onshore winds and ______ atmospheric pressure systems also called the sea surface to _____ temporarily.

Answer 15

Daily
Low
Rise

Question 16

Draw time line of global sea level

Answer 16

Refer to textbook

Question 17

Climate change causes changes in

Answer 17

Sea level

Question 18

Change in average temperature between 1900 and 2016

Answer 18

1.08 C

Question 19

Causes of climate change and HOW they cause it

Answer 19

Human activities (deforestation and burning fossil fuels)

Increase conc of greenhouse gases, these absorb outgoing long-wave radiation, so less is lost to space

As more energy is trapped the plant warms up

Question 20

Impacts of climate change

Answer 20

Increase in sea level through melting ice sheets and thermal expansion of water in oceans

Question 21

Global sea level is currently rising at _mm per year

Answer 21

2

Question 22

Impacts of climate change on coastal areas…

Answer 22

• More frequent and severe coastal flooding
• Submergence of low-lying islands
• Changes in the coastline, e.g island formation
• Contamination of water sources and farm land (salt)
• More coastal erosion and stronger storms

Question 23

SEA LEVEL FALL results in

Answer 23

Coastlines of emergence

Question 24

Landforms of emergence (3)

Answer 24

Raised beaches
Relict/fossil cliffs
Marine terraces

Question 25

Raised Beaches Formation? Example?

Answer 25

Formed by wave action Fall in sea level/rise in land puts beach beyond the waters reach at the high tide mark West Coast of Scotland

Question 26

Marine terraces Formation? Example?

Answer 26

Sea level falls Wave cut platforms exposed Land uplifted Platforms preserved as terraces above the ocean Croatia

Question 27

Relict/fossil cliffs Formation? Example?

Answer 27

The cliffs are no longer exposed by the sea and slowly get covered by vegetation These raised features are gradually weathered over time

Question 28

SEA LEVEL RISE results in

Answer 28

Coastlines of submergence

Question 29

Landforms of submergence

Answer 29

Rise Fjords Dalmatian coastlines

Question 30

Rias Formation? Example?

Answer 30

Water enters a valley and partially submerges it Rias have a gentle long and cross profile Wide and deep at mouth Narrower and shallower inland Milford Haven, South Wales

Question 31

Fjords Formation? Example?

Answer 31

Movement of a glacier that cuts rock formations Steep ridges formed on each side of glacial valley Valley fills with water Western Norway

Question 32

Dalmatian coastlines Formation? Example?

Answer 32

Valley lies parallel to coast Increase in sea level Valley flooded Islands left parallel to the coastline Named after the Dalmatian coast in Croatia

Question 33

The sea level changes due to 2 factors

Answer 33

Subsistence of the coastline | Increase in water volume of the ocean

Question 34

Subsistence

Answer 34

Coastal areas sinking - often this is due to access groundwater extraction. Has the effect of making the sea level higher

Question 35

Water volume

Answer 35

Changes due to either thermal expansion or addition of extra water from land stores (ice melt)

Question 36

Processes _____ and _____ landforms over time

Answer 36

Create | Alter

Question 37

Individual ________ combine to form _________. Coastal landscapes can be dominated by ________ or _________ but both are formed by both

Answer 37

Landforms Landscapes Erosion Deposition

Question 38

A change in one factor leads to changes in others. Example?

Answer 38

Change in wind direction could increase deposition and change a landscape dominated by erosional landforms to one dominated by depositional landforms

Question 39

Changes can occur over a range of _____ scales and ______ scales

Answer 39

Spatial Temporal E.g storm - hours Tectonic uplift - thousands of years

Question 43

The Maldives: Sea Level Rise

Answer 43

3mm per year Airport - 1.2m above sea level, only point of access 1.2 million tourists per year 1/3 of GDP tourism